Puraskar (1970)

Rakesh and Sumesh are two plain-clothes agents in the city's Criminal Investigations Department. They have been entrusted the task of locating a missing, believed to be abducted scientist, Mr. Das. They are assisted in this search by Renu Das, the daughter of Mr. Das. They manage to locate Mr. Das, and bring him safely to his house. His daughter is delighted to have her dad back. But then a series of odd coincidences lead Renu to conclude that her father has changed for the worse since she last saw him.